Author Archives: M0TAZ

RSGB AFS Phone Contest

On Saturday 16th January George M1GEO, Chris G8OCV and Dave M0TAZ took part in the RSGB AFS phone contest. The idea was to give the Secret Nuclear Bunker Contest Groups first outing of the clubs call MX0SNB. The clubs contest site benefits from having a large doublet antenna (40m per leg) 30m up on the large onsite mast.

Using the Icom 7100 and 100w we noticed quickly while it was possible to match the antenna it didn’t seem to be working very effectively.  The shack is located 20m below ground, in the original Home Office radio room. Once inside the bunker you have no idea what may have occurred. We decided to go back up to the mast and check, and on taking the doublet down we discovered one of the 300 Ohm feeder legs had become detached.

The antenna is located close to 30m above the ground, and the mast is already very well elevated, making it sometimes hard to maintain a working HF antenna in the winter weather. A quick fix later and we was soon back on the air.

George M1GEO

We operated from 3 till 5 PM and managed to work over 100 stations. The contest was well supported with many club stations and members from around the country. It was just a casual entry, but enabled us to get our club call on the air. Thanks to everyone we worked. 73 MX0SNB

RSGB 21/28 MHz contest

The RSGB contest provided an ideal opportunity to focus activity on the higher HF bands. Previous John M0UKD and I had built beams for  28 MHz 3e beam and  21 MHz 4e beam using the design on DK7ZB website.  28 MHz is a compact design using a 3m boom, and 21 MHz is somewhat bigger at 5m boom.

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The Racal PU12 mast was used for the 28 MHz antenna and Clark 10 for the 21 MHz antenna. Power was provided by the Honda 2KW silent generator and the radio was provided by George M1GEO the Icom 7700 delivering 200w RF.

21317020033_44fe6db48c_zThe operating was alfresco as the October weather was  sunny and warm. The shack table was positioned close to the mast ready for armstrong rotation The Clark mast was modelling some new blue legs, recently fabricated by Brian 2E0FHU. They worked perfectly and once assembled they provided a sturdy base.

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A quick check with the MFJ analyser confirmed the antenna was spot on resonance, and so the CQ calling could commence.

Despite a valiant effort on both 21 and 28 MHz conditions did not support the number of QSO we had hopped, in fact you could say it was a challenge to work anyone at times. QSO could be hard to tease out, and we decided the best method was to work anyone we could  hear. Some big DX did arrive, as we managed to work ZS6AI, ZS5DCF, CX8DS, VP8NO and PS8BR to name a few. The bands did seem to be open, at one stage we listened to a CW beacon in South America that was very loud (apparently 10w).

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Despite the lack of activity or poor band conditions we enjoyed our time operating outdoors in the sunshine.

Both homebrew beams worked well, and this may well be the last time we operate outdoors in 2015.

Further picture from the day are available online.

Thanks to everyone we worked 73 Dave M0TAZ, George M1GEO and John M0UKD

EDIT (30 November 2015)

The RSGB results come through today, and we were pleased to have won the Powditch Trophy for the Leading UK Multi-Op station achieving the highest score on 28MHz. With the help of the team, M0TAZ M0UKD and G3SVK (G8OCV in support).

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Antenna Maintenance

Exposed on the side of a 50 meter mast the antenna often requires maintenance. George M1GEO and Chris G8OCV have over the years perfected the best way to mount the antenna, and on this occasion is had lasted close on 2 years. Antenna maintenance in the afternoon sun is much preferable to winter rain, so we too advantage of the weather to pull up the new doublet antenna. The doublet is 40m per leg, into 300 Ohm ladder line and then a 4:1 Balun.

The doublet is 40m per leg, into 300 Ohm ladder line and then a 4:1 Balun.

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The centre of the antenna is made from a plastic chopping board from one of the discount value stores, ideal for insulators. The wire is multi strand 13A flex, ideal for antennas and hopefully robust enough to survive the winter weather.

The centre of the antenna is pulled up onto the mast, elevated to 20m and the ends are on one side into a tree and the other a warning siren. Its quite difficult to locate suitable points for the antenna ends, and elevation without snagging in the local trees is always a challenge. Once setup we managed a couple of QSO on 80m.

73 Dave M0TAZ, George M1GEO, Chris G8OCV

Practical Wireless 70 MHz contest

The popular shortwave and ham magazine Practical Wireless runs a 70 MHz contest once a year. The contest attracts a number of entries from all around the country, including one keen team who climb Helvelyn in the Lake District (M0BKQ/P).  M0TAZ’s entry didn’t include a 900m accent to the top of a mountain, since we operated from the Kelvedon Hatch Secret Nuclear Bunker. The location is around 130m ASL and affords nice views over the Essex countryside.

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The Setup  

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The activity started at 1pm and finished at 5; activity levels were moderate, with the first 2 hours being the most active. Many portable stations operate 10w or less so the amplifier and 160W did mean we sometimes had to listen very carefully to get a calling station’s details! People often assume that because they can hear you loud and clear, that their signal must also be good. The weather was sunny and this must have helped encourage people to operate portable outdoors.

We managed to work 47 stations: Our best DX was Scotland GM4JR at 454 km, and we were also pleased to work into Wales GC0VPR/P, GW0EIY/P and GW4EVX/P and also the Netherlands PA4VHF.

The QSO map pins indicates the location and number of stations worked.

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Many thanks to John M0UKD for the use of his beam and 70 MHz amplifier, both worked flawlessly and George M1GEO, Dave M0YOL and Chris G8OCV for assistance with the mast and words of encouragement.

While we were busy on 70 MHz, some of the other guys were having a crack at the CQWW RTTY contest, which was also well underway.

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Further pictures are available online.

Thanks to everyone who called, and hope to work you again soon.

73 Dave M0TAZ